Suspension strut

ABSTRACT

A suspension strut adapted to be connected between a vehicle frame and a wheeled axle. The suspension strut includes an elongated housing which is divided by a transverse wall into upper and lower sections, each of which contains a plurality of rubber pads. The opposite ends of the suspension strut are closed by end cap members which are independently adjustable for preloading the strut and are movable relative to the housing in a longitudinal direction for causing the rubber pads to be alternately compressed and expanded.

[451 July 4,1972

Boschi [54] SUSPENSION STRUT [72] Inventors: Frank R. Jellison, Canton;John B. Mason, Prima E G d ry xammer ll 00 man "e both of Oh); TerryMcQueen AttorneyJ. L. Carpentefand E. J. Bliskup Princeton, Ind.

Detroit A suspension strut adapted to be connected between a vehicle[73] Assignee:

General Motors Corporation, Mich.

frame and a wheeled axle. The suspension strut includes an [22] Filed:Nov. 24, 1970 [21] Appl.No.'. 92,420

elongated housing which is divided by a transverse wall into upper andlower sections, each of which contains a plurality of rubber pads. Theopposite ends of the suspension strut are closed by end cap memberswhich are independently adjustable for preloading the strut and aremovable relative to the ....B60 11/24 52 Field ofSearch............................280/124 R; 267721, 63 housing in alongitudinal direction for causing the rubber P to be alternatelycompressed and expanded.

[521 511 lnt.Cl.................

3 Claims, 4 Drawing Figures References Cited UNITED STATES PATENTS3/1968 Doennecke...........................

SUSPENSION STRUT The invention concerns a suspension strut for use withan off-highway truck that is characterized in that the strut utilizes aplurality of rubber pads arranged in a manner so as to provide good ridecharacteristics when the vehicle is loaded and unloaded. Moreparticularly, the suspension strut according to the present invention isdivided into two cushioning sections, each of which includes a pluralityof rubber-type pads. One of the cushioning sections serves as theprimary spring support when the vehicle is unloaded and is graduallyrendered ineffective as the vehicle is loaded. Thereafter, the othercushioning section serves as the primary spring support for the heavilyloaded vehicle.

In the preferred fonn, the suspension strut according to the inventionincludes an elongated housing having a pair of laterally spacedlongitudinally extending openings formed in one end of the housing. Theother end of the housing is formed with a single longitudinallyextending opening and is separated from the aforementioned pair oflongitudinally extending openings by a transverse wall rigidly formedwith the housing. A first end cap member has a portion adapted to beconnected to a vehicle frame and another portion formed with a pair oflaterally spaced pistons. The end cap member is connected to the housingby a pair of longitudinally extending guide rods which position thepistons within the pair of openings formed at one end of the housing. Asecond end cap member has a portion that is adapted to be connected to awheeled axle and another portion formed with a single piston. As in thecase of the first end cap member, a pair ofguide rods connect the secondend cap member to the housing with the piston located within the singleopening formed therein. A plurality of rubber pads are located in eachof the longitudinally extending openings between each of the pistons andthe transverse wall for permitting the rubber pads to be alternatelycompressed and expanded as a result of longitudinal movement of the endcap members relative to the housing.

The objects of the present invention are to provide a suspension strutdivided into two cushioning sections and having a plurality of rubberpads located in each of the sections in a manner so as to provide dualstage ride characteristics; to provide a suspension strut for a vehiclewhich includes a plurality of rubber pads arranged in a series-parallelfashion so as to provide good ride characteristics when the vehicle isloaded and unloaded; to provide a suspension strut for a vehicle havingtwo cushioning sections, each of which is provided with a plurality ofrubber pads, with one cushioning section being primarily effectiveduring a first range of loads and the second cushioning section beingeffective during a heavier range of loads; to provide a suspension struthaving two sets of rubber pads located at opposite ends of the strut andseparated from each other in a manner so that each set can beindependently preloaded to a predetermined load level; to provide a ridestrut for a vehicle having an elongated hollow housing which is dividedby a transverse wall into a pair of axially spaced cushioning sectionshaving a plurality of rubber pads; and to provide a rubber strutsuspension device for a vehicle having a pair of end cap members, eachof which is movable relative to a support housing a varying amountdepending upon the load placed on the strut.

Other objects and advantages of the present invention will be moreapparent from the following detailed description when taken with thedrawings in which:

FIG. 1 is an elevational view showing a vehicle suspension arrangementincorporating a suspension strut made in accordance with the invention;

FIG. 2 is an enlarged view of the suspension strut shown in FIG. 1 withcertain parts broken away so as to show the interior of the strut;

FIG. 3 is a sectional view taken on line 3-3 of FIG. 2; and

FIG. 4 is a sectional view taken on line 4-4 of FIG. 2.

Referring to the drawings and more particularly FIG. 1 thereof, asuspension arrangement for a vehicle is shown comprising a transverseaxle 10, the opposite ends of which are provided with rotatable wheels,one of which is shown in phantom lines and indicated by the referencenumeral 12. The axle 10 is integrally formed with a forwardly extendingyoke member 14 connected by a ball and socket arrangement 16 to adepending bracket 18 rigidly secured with the vehicle frame 20. Locatedbetween the frame 20 and the axle 10 are a pair of suspension struts 22made in accordance with the invention and serving as spring devices forresiliently supporting the vehicle chassis and cushioning oscillatorymovement of the axle 10. Only one suspension strut 22 is shown and it isgenerally vertically orientated with its lower end connected by apivotal connection 24 to the axle 10, while the upper end is connectedby a pivotal connection 26 to the frame 20.

More specifically and as seen in FIG. 2, the suspension strut 22comprises an elongated housing 27 having an upper cushioning section anda lower cushioning section. The upper cushioning section is formed bythree vertically orientated walls 28, 30 and 32, each of which isrigidly secured at the vertical edges thereof to the upper portions of apair of side walls 34 and 36. The wall 30 is located in a plane parallelto the planes of walls 28 and 32 and is positioned midway between thelatter-mentioned walls. Thus, a pair of generally rectangular elongatedopenings are formed in the upper cushioning section of the housing 27and each opening is filled with a plurality of rectangularly shapedrubber-type pads 37 which rest on a transverse wall 38 that is rigidlysecured to the lower edges of the walls 28, 30, 32 and to the side walls34 and 36.

The lower cushioning section of the housing 27 is formed by the lowerportion of the side walls 34 and 36 and a pair of vertically orientatedwalls 40 and 42. The upper ends of walls 40 and 42 are rigidly connectedto the transverse wall 38, while the side edges are fixed with the sidewalls 34 and 36. Thus, as seen in FIG. 3, the lower cushioning sectionhas a single elongated opening which is rectangular in cross section forsupporting a plurality of rectangularly shaped rubber-type pads 44. Inthis regard, it will be noted that the pads 37 and 44 are identical inconstruction, each comprising a rectangular base plate 46, one or bothsides of which is bonded to a layer 48 of elastomeric material.

The upper cushioning section of housing 27 is closed by an end capmember 50, the upper portion of which includes an eyelet mount 52 whichconstitutes one part of the pivotal connection 26. The eyelet mount 52is rigidly secured to the upper surface of a rectangular plate member 54by a pair of end supports 56 and 58. The lower" surface of the platemember 54 is formed with a pair of spaced pistons 60 and 62, each ofwhich includes an end plate 64 corresponding in configuration to thecross sectional configuration of the openings in the upper cushioningsection of the housing 27. The pistons 60 and 62 are adapted to registerwith the openings, engage the upper ends of the rubber pads 37 locatedtherein, and move relative to the housing 27 along the longitudinal axisthereof. In order to realize such movement, a pair of guide rods 66 and68 are located on opposite sides of the suspension strut 22 with thelower end of each guide rod being connected by a nut 70 to an outwardlyprojecting; ear 72 rigidly secured to the associated side wall. Theother end of each guide rod terminates with a rigidly formed enlargedhead 73 and has an intermediate portion slidably received within an car74 rigidly connected to the plate member 54.

As in the case of the upper cushioning section, the lower cushioningsection is formed with an end cap member 76, the lower end of which hasan eyelet mount 78 which constitutes one part of the pivotal connection24. The eyelet mount 78 is rigidly attached to a rectangular platemember 80 by a pair of end supports 82 and 84. The upper surface of theplate member 80 is formed with a single piston 86 having an end plate 88which corresponds in configuration with the cross sectional shape of theopening and is adapted to engage the lower end of the stack of rubberpads 44 in the lower cushioning section. The end cap member 76 is alsomovable along the longitudinal axis of the housing 27 and guidance isprovided by a pair of guide rods 90 and 92, the upper ends of which aresecured by nuts 93 to ears 94 and 96, respectively formed with theoffset portions of side walls 34 and 36 as seen in FIG. 3. The lowerends of the guide rods 90 and 92 terminate with integral enlarged heads97 and are slidably received within ears 98 and 100, respectively,rigidly connected to the upper surface of the plate member 80.

One advantage of the suspension strut 22 described above is that theupper and lower cushioning sections can be independently preloaded so asto provide desired ride characteristics when the vehicle is loaded andunloaded. In this regard, it will be noted that the lower cushioningsection has a single row of rubber pads 44 which is preloaded bytorquing the nuts 93 while the upper cushioning section has a double rowof rubber pads 37 which are preloaded by torquing the nuts 70. By properpreloading of the cushioning sections, it is possible to permit thesingle row of rubber pads 44 to serve as the primary spring means whenthe vehicle is unloaded. Under such circumstances, both cushioningsections will support the weight of the vehicle, however, the end capmember 76 will move the greater distance relative to the housing 27 andcause compres sion and expansion of the rubber pads 44 during jouncingof the axle. As the vehicles load is increased, the end cap member willgradually move upwards compressing rubber pads 44 until the plate member80 contacts the lower end of the housing 27. At such time, the end capmember 76 and the housing 27 will, in effect, be one single rigid unitand the rubber pads 37 in the upper cushioning section will serve as theprimary spring support and the ride characteristics will be determinedthereby. It will be noted also that each of the guide rods 66, 68, 90and 92 has an elastomeric bumper 102 located between the enlarged headand the associated ear for cushioning axle rebound.

Various changes and modifications can be made in this constructionwithout departing from the spirit of the invention. Such changes andmodifications are contemplated by the inventors and they do not wish tobe limited except by the scope of the appended claims.

We claim:

1. A suspension strut adapted to be connected between a vehicle framemember and a wheeled axle member, said suspension strut comprising anelongated housing having a longitudinally extending opening formed ineach end of said housing, a transverse wall rigidly formed with saidhousing and separating said longitudinally extending opening formed ineach end of said housing, a first end cap adapted to be connected tosaid vehicle frame member and having a piston, first means connectingsaid first end cap to one end of said housing for relative longitudinalmovement therebetween with said piston registering with one of saidlongitudinally extending openings, a second end cap adapted to beconnected to said wheeled axle member and having a piston, second meansconnecting said second end cap to the other end of said housing forrelative longitudinal movement therebetween with said latter-mentionedpiston registering with the other of said longitudinally extendingopenings, a plurality of resilient pads located in each of saidlongitudinally extending openings between each piston and saidtransverse wall for alternate compression and expansion as a result oflongitudinal movement of the end caps relative to the housing, saidfirst means including a guide rod having a threaded connection forpreloading the resilient pads in said one of said longitudinallyextending openings, and said second means including a guide rod having athreaded connection for preloading the resilient pads in said other ofsaid longitudinally extending openings.

2. A dual stage variable rate suspension strut adapted to be connectedbetween a vehicle frame member and a wheeled axle member, saidsuspension strut comprising an elongated housing having a pair oflaterally spaced longitudinally extending openings formed in one end ofsaid housing and a single longitudinally extending opening formed in theother end of said housing, a transverse wall rigidly formed with saidhousing and dividing said pair of longitudinally extending openings fromsaid single longitudinally extending opening, a first end cap adapted tobe connected to one of said members and having a pair of plungersections, means connecting said first end cap to said housing forrelative longitudinal movement therebetween with said pair of plungersections registering with said pair of longitudinally extendingopenings, a second end cap adapted to be connected to the other of saidmembers and having a single plunger section, means connecting saidsecond end cap to said housing for relative longitudinal movementtherebetween with said single plunger section registering with saidsingle longitudinally extending opening, and a plurality of rubber padslocated in each of said longitudinally extending openings between eachplunger section and said transverse wall for alternate compression andexpansion as a result of longitudinal movement of the end caps relativeto the housing.

3. In combination with a vehicle having a frame member and a wheeledaxle member, a dual stage variable rate suspension strut adapted to beconnected between said frame member and said axle member, saidsuspension strut comprising an elongated housing having a pair oflaterally spaced longitudinally extending openings formed in one end ofsaid housing and a single longitudinally extending opening formed in theother end of said housing, a transverse wall rigidly formed with saidhousing and separating said pair of longitudinally extending openingsfrom said single longitudinally extending opening, a first end capadapted to be connected to one of said members and having a pair ofpistons, first means connecting said first end cap to said housing forrelative longitudinal movement therebetween with said pair of pistonsregistering with said pair of longitudinally extending openings, asecond end cap adapted to be connected to the other of said members andhaving a single piston, second means connecting said second end cap tosaid housing for relative longitudinal movement therebetween with saidsingle piston registering with said single longitudinally extendingopening, a plurality of rubber pads located in each of saidlongitudinally extending openings between each piston and saidtransverse wall for alternate compression and expansion as a result oflongitudinal movement of the end caps relative to the housing, saidfirst means including a pair of guide rods located outboard of saidhousing and each having a threaded connection for preloading the rubberpads in said pair of longitudinally extending openings, and said secondmeans including a pair of guide rods located outboard of said housingand each having a threaded connection for preloading the rubber pads insaid single longitudinally extending opening.

1. A suspension strut adapted to be connected between a vehicle framemember and a wheeled axle member, said suspension strut comprising anelongated housing having a longitudinally extending opening formed ineaCh end of said housing, a transverse wall rigidly formed with saidhousing and separating said longitudinally extending opening formed ineach end of said housing, a first end cap adapted to be connected tosaid vehicle frame member and having a piston, first means connectingsaid first end cap to one end of said housing for relative longitudinalmovement therebetween with said piston registering with one of saidlongitudinally extending openings, a second end cap adapted to beconnected to said wheeled axle member and having a piston, second meansconnecting said second end cap to the other end of said housing forrelative longitudinal movement therebetween with said latter-mentionedpiston registering with the other of said longitudinally extendingopenings, a plurality of resilient pads located in each of saidlongitudinally extending openings between each piston and saidtransverse wall for alternate compression and expansion as a result oflongitudinal movement of the end caps relative to the housing, saidfirst means including a guide rod having a threaded connection forpreloading the resilient pads in said one of said longitudinallyextending openings, and said second means including a guide rod having athreaded connection for preloading the resilient pads in said other ofsaid longitudinally extending openings.
 2. A dual stage variable ratesuspension strut adapted to be connected between a vehicle frame memberand a wheeled axle member, said suspension strut comprising an elongatedhousing having a pair of laterally spaced longitudinally extendingopenings formed in one end of said housing and a single longitudinallyextending opening formed in the other end of said housing, a transversewall rigidly formed with said housing and dividing said pair oflongitudinally extending openings from said single longitudinallyextending opening, a first end cap adapted to be connected to one ofsaid members and having a pair of plunger sections, means connectingsaid first end cap to said housing for relative longitudinal movementtherebetween with said pair of plunger sections registering with saidpair of longitudinally extending openings, a second end cap adapted tobe connected to the other of said members and having a single plungersection, means connecting said second end cap to said housing forrelative longitudinal movement therebetween with said single plungersection registering with said single longitudinally extending opening,and a plurality of rubber pads located in each of said longitudinallyextending openings between each plunger section and said transverse wallfor alternate compression and expansion as a result of longitudinalmovement of the end caps relative to the housing.
 3. In combination witha vehicle having a frame member and a wheeled axle member, a dual stagevariable rate suspension strut adapted to be connected between saidframe member and said axle member, said suspension strut comprising anelongated housing having a pair of laterally spaced longitudinallyextending openings formed in one end of said housing and a singlelongitudinally extending opening formed in the other end of saidhousing, a transverse wall rigidly formed with said housing andseparating said pair of longitudinally extending openings from saidsingle longitudinally extending opening, a first end cap adapted to beconnected to one of said members and having a pair of pistons, firstmeans connecting said first end cap to said housing for relativelongitudinal movement therebetween with said pair of pistons registeringwith said pair of longitudinally extending openings, a second end capadapted to be connected to the other of said members and having a singlepiston, second means connecting said second end cap to said housing forrelative longitudinal movement therebetween with said single pistonregistering with said single longitudinally extending opening, aplurality of rubber pads located in each of said longitudinallyextending openings between each piston and saId transverse wall foralternate compression and expansion as a result of longitudinal movementof the end caps relative to the housing, said first means including apair of guide rods located outboard of said housing and each having athreaded connection for preloading the rubber pads in said pair oflongitudinally extending openings, and said second means including apair of guide rods located outboard of said housing and each having athreaded connection for preloading the rubber pads in said singlelongitudinally extending opening.